Sound-reproducing machine



Oct- 15, 1929- F. B. MITCHELL SOUND REPRODUCINQ MACHINE 2 Sheets-Sheet; 1

Filed July 17, 1923 ElRMI/'oibell Oct. 15, 1929 F. B. MITCHELL SOUND REPRODUCING MACHINE Filed July 17, 1923 2 snets-sneet '2 n.11 onlllllllllllllL-wl f .Mm .AJ 3 l l w@ IJIII P 1 ,f 7 E A m .l F. DJ

Patented. Oct. l15, 19.29'

Unirse STATES i PATENT Iorrica FRANK BOWLEY MITCHELL, OF HOVE, EN'(arLAlYFvI-ly SOUND-REPRODUCING MACHINE Application filed my' i7, 1923,' serial No. 652,154, and in Great Britain July'ao, 19722.

This invention relates'to sound-reproducing machines with particular reference to the stylus or primary sound-reproducing agent employed in connection with such machines.

Hitherto it has been usual to form the stylus as a hard tapered-needle which requires constant renewal as it is practically rendered uniitted for use after playing through one or a relatively small number of records.

The object of the present invention is to devise an improved form of stylus wherein this disadvantage will be completely obviated, since a machine constructed and arranged in accordance with my invention will be capable of playing through a very large number of records without requiring any alteration or renewal of stylus.

With this and other objects in view, the invention consists in the variousk details and 'combinations of parts hereinafter described and more particularly pointed out lin the appendant claims. Y

The accompanying drawings illustrate several modes of carrying out the invention :e

Figures 1 and 2 are front lelevations showing one convenient form oi reproducer in accordance with my invention with the parts v shown in different positions; i

Figures 3 and 4l are front views illustrat- 39' ing cert-ain ofthe part-s shownin Figures 1 and 2 in different positions;

Figure 5 is a sectional view showing :the

stylus holder of Figures l and 2, and

Figure 6 is a front view showing the component parts of the stylus holder in Figure 5.

Figure 7 illustrates a perspective view of the stylus holder;

Figure8 is an elevation showing a' portion or" a modified form ofreproducerin accordance with the invention;

Figures 8, 9, and 10 show a still further modiiication'with the parts invarious positions;V v f v Fig. 11 is a sectional view of a modied form offstylus holder.

vFigure 12 is a sideelevation of a further modilication of apparatus in accordance with the invention; Y F igurel isa perspective view showing a modification similar to Figure 12;

Figure 14 is a view of a still further modilication; l

Figures 15 and 16 are side views of the modification of Figure 14, f

Figures 17 and 18 are views illustrating de- 55 tails, and

Figure 19 isa view illustrating the lower y end of the lever a.

In carrying my'invention into effect in one convenient manner and as illustrated, for eX- ample, in Figures 1 to y6, I form my improved reproducer with a groove in one part of its periphery in which is arranged a bent lever'a pivoted in some convenient position" as ath" and normally retained in its outer position (as shown in Figure 1) b v means of a suitable i spring, such as c. The reproducer is tted with the usual stylus bar al to which issecured, (as, for example, by a screw e) a holder (indicated generally by the reference. finy Figures 1 and 2 but hereinafter described lin greater detail) ythrough which is passed a fine wire g of a gauge equal approximately to they f width of a groove in the'sound record so 'that suchwire may serve as the stylus for the iri'al75 chine and being of approximatelythe same v diameter or gauge as the width of a sound.

Y groove may be continuously used forl the play-` ing of records until the whole of the wire provided has beenworn away,

manner I am able on theone machine, withf y lout renewal vor alteration of the stylus, to play :through a verylarge numberL of records.'y

As the wire is of relatively ine'lgaugefit" will, infgeneral, require Vto begripped closee to the operating point in order to give 4itt-he necessary stiffness to enable it to operate'fas astylus and in conjunction, therefore, with my improved apparatus I prefer lto provide t means by which the wire may be so gripped, but in a releasable manner, so that when .the portion of the wire vprotruding from v its holder is worn away the gripping means may Vbe released to allow a further portion of wirel to be protruded, and I further prefer to .pro 9'5 vide a gauge stop of suitable form in order to limit the amount of the wire so protruded. Such gripping means and gauge stop may be actuated kby hand or may Vbe actuatedautomatically by the operation of removing the i soV that in this so Figure 1l shows a Y grip but having a flat reproducer from a record and allowing the same to rest upon a suitable support or a combination of these methods may be adopted or any other convenient means may be employed for the same purpose.

In the form illustrated in Figures l to V6 the gauge stop and wire releasing means are Vadapted to be actuated by hand pressure, tor

which purpose the bent lever a above referred to is adapted to cooperate with a Alever or like member h having a hook end ory eX- tension it adapted to engage a lug er projection upon a lever z' pivoted by means et a slot z" about a pin 2 and bent at its end Z3 so as to forma stop for the wire g. rlChe lever is normally kept Vin the position shown in Figure 2 (that is, out of the path et the wire) by means of a bent spring 7c and the wire gripping means to be presently described is operated by the lever Z.

In theform shown in Figures 5 and 6 the wire gripping means comprises a V- or channel-shaped member Zl adapted to receive a wedge-piece Z2 which is pivoted at Z3 to the lever Z, the latter being also pivoted at ZLt tothe channel-member Z. A spring or other means (not shown) may be provided to maintain the lever Z in the normal position in which the wedge is inserted into the channel member for the purpose orn gripping the wire.

The arrangement is such that hand pressure on the circumference olf the reproducer casing causes an inward movement oi the lower end of the lever a (which is normally Vin the position shown in Figure 2) into the position shown in Figure 3 so that it operates the lever h to move the stop lever r'. into the position in which the stop lportion comes into the path of the wire, a suitable stop (not shown) being provided to prevent further movement of the gauge member Further inward movement ot' the lever a does not alter the position or" the'gauge meinl but theend kof the lever a presses upon the upper part o1" the lever Z, thus withdrawing the wedge from within the channel and ailowing the wire to drop into Contact with the gauge stop. On releasing'the reproducer theV wire is again gripped and the gauge step is moved out of the way so that the apparatus is ready for re-use.

If necessary or desirable, the upper of the wire g may bev formed with a reinforcing or strengthening head g'.Y

modified term ot member m to A wire instead of the wedge shown in Figure 6.

vIn this case the V oi' the holder is so small that the wire partially protrudes therefrom and in order to prevent point Contact with the wire, which might tend to bend the saine, I provide a small spring fm between the wire and the gripping or holding device.

It is obvious that the lifting of the tone arm may be made to operate the parts in place of the hand pressure above referred to, and one arrangement this case the reproducer is provided with an extension plate a to which is secured at one end a spring a2 while the other end carries a pin or pivot-like part aL adapted to engage in a recess in the gauge or stop lever z', the latter being also provided with a second recess in which enfraffes a in a5 carried b a spring a which is somewhat stronger than the spring a2 and which is secured to a lever a7 pivoted to the plate a about the centre as and carrying a pin a9.

The arrangement is such that upon pressby which this may be elected is shown in Figures 8 to l0. ln'

ing the lever a7 upwards (either by hand or f -further upward movement causes the gaugeL member z' to be moved upwards, as shown in Figure 10, in which position it is arrested to gauge the amountof wire to be protruded when the wire-gripping device is released. Still further upward movement of the lever 057 causes the pin a to move the grip-releasing lever Z so that the wire is allowed to lmove outwards into contact with the gauge and on releasing the pressure on the lever a7 the wire is gripped in this position by the4 mechanism controlled by lever Z and then the gauge e' moved back to the normal position shown in Figure 8.

Figure v8 s ows a simple hand-operated arrangement in which the wire g is held in the holder f by the grip of the lever Z, and the gauge stop in this construction takes the form of a lever z having a quadrant 2 thereon adapted to Vbe actuated by a rack 3 on the end of a spring-controlled lever i4.' On pressing this lever inwards towards the reproducer 'the gaugestop 21 1s rotated into the path of the wire g, while further 'movement of the lever causes the projection @'5- thereonto move into contact wit, vthe lever Z,

vthus releasing the wire to contactvwith the gauge stop, in a manner as previously described, release of the pressure on the lever hereinafter described 12o 4 causing the wire to be gripped in its gauged v againlock the'stylus; or, if anotherform is used, the wire maybe pulled up by avpermanent magnet.

Figure 13 shows a modicationvvhich is somewhat similar to those `heremberore described but-in, which the-release of the Wire isV eliectedby the removing of the reproducer from a record and allovving the same` to rest upon a support. The dotted ,linesshow the paths through Which the` lower part of the holder and the outerl side of the tone arm are moving'.- In this form the reproducer n is provided With a holder f having the Wire g gripped vtherein by means actuated by the lever Z and outside the record n I arrange a `rest .n2 for the reproducer, the parts being brought' to their correct position by contact of the tone arm n3 with the stop pin n4. When the reproducer is thus positioned on the part n2 the member 0 carried-by the spring o2 Iwhich is attached by a-screW (not shown) to the back of a2 .acts as the gauge stop andthe Wire g is released for movement into contact With' the gauge stop by the edgel a5 of the member a2. moving the grip-releasing lever Z.

Figure 12 shov'vs amodiication of the arrangement shown in Figure 13 in which instead of the iiat springo2 for supporting the gauge stop o the latter is supported by means of a helical -spring 03, While the extent of the gauging maybe adjusted by means of the stud or set-screw o4. The gauge stop of may be suitably attached to m2 by a dovetail fitting05 In each Case the object of the spring (o2 m Figure 13 and o3 in Figure 12) is to maintain the gauge in action until after the .gripping of the-Wire has'been eliected by the removal of the reproducer from the rest, the lever Z after such removalbeing returned'to its nori mal or gripping position by means oi a suitable spring mounted behind on its spindle 6. A modified form of reproducer is shown in Figures 14 to 18 Where the operation of renewing the Working point of the stylus is AVcaused by rotary movement of the reproducer about the centre of the diaphragm. In this modification the reproducer can rotate upon the tone arm to Which it is suitably attached in any Well known manner.` The tone arm carries a fixed rack p and lug p a front vieW of which is shown in Figure 17 and an end view in Figure 15. The rack and stop are omitted from Figure 16 in order to avoid confusion. In 'addition to the Wire-gripping device f which, by means of a projection f is held by screw e in the ordinary needle holder, and Which'is actuated by lever Z, the reproducer also carries a pinion p3 Which coacts With the fixed rack p. When the reproducer is rotated with the center of the diaphragm as centre of rotation, the pinion p3 moves alongv rack py andI is itself rotated, thus causing movement of gauge stopl p2, to Which it is a tached, into position inthe pathof the Wire. The movement of the end 'of p2 is shown by the chain-dotted arcv in Figure 14. Thelug p then contacts Withthe end of lever Z as shown in Figure 15 and upon further movement moves it to release the Wire Which,.as

before, falls on to the gauge 292. Backwardk rotation of the reproducer first moves p :out of contact Vvvith Z Which returns under spring control to cause the Wire to be again gripped. f

@2 .is then moved to its normal position by means of pinion p3 and .rack p,

and the reproducer is again ready foruse.

`It Will be understood that the means adopted for holding the Wire and the arrangements provided for gauging the amount of Wire to be protruded When a part of the. Wire has been Worn away, as also the means adopted for operating'the Wire-gripping and gauging parts, may be variously modied according to the kindrof machine to Which the invention is to be applied or any practical requirements thatmay have to be fulfilled. i

Further, in all cases Where necessary or desirable the Wire g (Fig-1) may be associated with a spring member g adapted to press the Wire outwards against the gauge When the grip is released and such spring may act upon a cup or like member g2 to facilitate the proper positioning of the Wire .when the holdstylus, means torgripping said stylus near its operative end and a` movable lever mount ed upon said sound-box independentof said stylus bar for 'operatingand releasing said grippermeans. 1 f y 2. Ina sound reproducing` machine the combination of a sound-box, a stylus formed of fine Wire, a stylus :bar or'supporting said stylus, spring actuated means for gripping said stylus near its operative end and ia movrv able lever mounted upon said sound-box independent of said stylus bar for-operating andreleasing said gripping means.

3. In asound reproducing machine the combination of a sound-box, a stylus formed of fine Wire, a stk lus bar supporting said stylus, means for ceding the stylus endWise, means for gripping said stylus near its operative end and a movable lever mounted upon said sound-box independent of said stylus bar v:tor operating and releasingsaid gripping means. 7 x f e 4. In a sound reproducing machine Ithe combination of a sound-box, a stylus formed of line wire, a stylus barl supporting saidY stylus, means for gripping said stylus near its operative end, means for feeding the stylus endWise, means carried on the soundbox independent of said stylus lbar for limiting the extent of such feed and a movable lever mounted upon said sound-box independent of said stylus bar for operating and releasing said gripping means.

5. In a sound reproducing machine the combination of a sound-box, a stylus formed of tine Wire, a stylus bar supporting said stylus, means for gripping said stylus near its operative end, spring means carried upon said sound-box independent of said stylus bar for feeding the Wire endWise,`means carried upon the sound-box independent of said stylus bar for limiting the extent of such feed and a movable lever mounted upon said sound-box independent of said stylus bar for operating and releasing said gripping means.

6. In a sound-reproducing machine the combination of a sound-box, a stylus formed of fine Wire, a holder for said stylus, means for gripping said stylus near its operative fend in said holder, means carried by the sound-box for feeding said stylus Wire end- Wise, a gauge stop also carried upon said sound-box for limiting the extent to which said stylus may be protruded from said holder, and a movable lever mounted upon said sound-box independent of said stylus holder for moving said gauge stop into or out of its operative positionY and for operating and releasing said gripping means.

7.*In a sound reproducing machine the combination of a sound-box, a stylus formed of fine Wire, a holder for said stylus, means for gripping said stylus in said holder,a movable gauge stop mounted upon saidl sound-box independent of said holder for limiting the extent to Which said stylus may be protruded from said holder and means also carried by said sound-box for operating both the gripping means and the gauge stop.

8. In a sound-reproducing machine the combination of a sound-box, a stylus formed of fine Wire, a holder for said stylus, spring means for gripping said stylus near its operative end in said holder, a movable gauge stop mounted upon said sound-box independent of said holder for limiting the extent to Which said stylus may be protruded from said holder, and means also carried by said soundbox for operating by one movement both the gripping means and the gauge stop.

9. In a sound-reproducing machine the combination of a lsound-box, a stylus formed of fine Wire, a holder for said stylus, means for feeding said stylus endwise, means for gripping said. stylus near its operative endy in said holder, a movable gauge stop mounted upon said sound-box independent of said holder for limiting the extent of feed of said stylus and a lever carried on said sound-box independently of said holder, saidlever operating first to move the gauge stop into gauging position, second, to release the stylus gripping means tol allow the stylus Wire to be fed up to saidy gauge stop, third, to. regrip vthe stylus in said holder and'iinally to replace the gauge stop in'its normal inoperative position.

l0; In a sound-reproducing machine the combination of a sound-box, astylusl formed of fine Wire, a stylus bar for supporting saidV stylus, means for gripping said stylus near its operative end,a movable lever mounted upon said sound-box independent of said stylus bar for operating and releasing said gripping means and a movable gauge stop a-lso mounted uponsaid sound-box With arrangements to move same underv the stylus point for adjustment of the stylus and then out of the way When the stylus is in operation on the record.

1l. In a sound-reproducing machine the combination of a sound-box, a stylus formed of tine wire, a holder for said stylus, means for feeding said stylus'endwise, spring means for gripping said stylus near its operative end in said holder, a movable gauge stop mounted upon said sound-box 'independent of said holder for limiting the extent of feed lof said stylus and a lever mountedupon said sound-box independent of said stylus holder, said lever operating rst to move the gauge stop into gauging position, second, to release said stylus gripping means to allow the stylus Wire to be fed up to said stop, third, to: regrip the holder in said stylus and finally to replace the gauge in its normal inoperative position.

l2. Apparatus according to claim 5 in combination with a rest upon said machine adapted to support the sound box, and coacting means upon said rest adapted to move the movablelever when the sound box is placed upon the rest. v i

In testimony whereof I have signed my name to this specification.

FRANK BOIVLEY MITCHELL. 

